Display systems often face the problem of painting a vector between any two points on a cathode ray tube screen. Depending on characteristics such as, time available to draw the vector, the refresh rate of the vector, the rate of change of the orientation of the vector, tube characteristics, and vector length; it is possible to get serious variations in intensity levels for individual vectors. The long vector being plotted may be hard to discern, while the short vector may exceed the safe operating point for the tube. In prior art systems, a simple charging voltage proportional to the X and Y coordinates of the vector is applied to integrators which are controlled by a fixed gate generator. Such a system can result in serious variations in writing speed and illumination intensity.